Cable ties are well known and generally include an elongated strap portion integrally formed with a head having a strap passageway which includes a strap locking mechanism for securing the strap around a bundle of wires or cables. Plastic cable ties having a metal locking wedge inserted within the strap locking channel of the head are well known in the art. U.S. Pat. Nos. 3,186,047 to Schwester, et al. and 3,408,699 to Reynolds are examples of two-piece cable ties utilizing a metal locking wedge. U.S. Pat. No. 3,408,699 teaches weakening the flexure restraining member at its flexure region, which is described as occurring at the contact between the metal locking wedge and the inner wall of the strap locking channel, in order to reduce the threading force of the strap. The additional modifications suggested by U.S. Pat. No. 3,408,699 increase the pull out force of the metal locking wedge by strengthening the flexure restraining member.
While a reduction in threading force and increase in pull out force are desirable, the teachings of Reynolds '699 require cutting out or otherwise removing material from the metal locking wedge which is complicated and involves extra procedures to remove scrap material. Additionally, the weakening of the flexure region of the metal locking wedge by removing material could result in the locking wedge breaking off at this weakened region during strap withdrawal failure that potentially could allow metal pieces to cause problems in the field. Therefore, improvement in the art is still required.
In general, an improved two-piece cable tie includes a strap having a first end and a free end, a locking head secured to the first end of the strap, a plurality of walls on the locking head forming a strap accepting channel, a metal locking wedge having a strap engaging portion positioned within the strap accepting channel and an embedded portion mounted within an inner wall of the locking head and a flexure region disposed therebetween, wherein the metal locking wedge includes a coined groove on the embedded portion of the locking wedge.